According to a report by Antony Kastrinakis of The Sun (subscription required), Barcelona are keen on signing Sergio Aguero from Manchester City this summer. Kastrinakis believes a bidding war with Real Madrid will ensue with the influence of Lionel Messi, Aguero’s friend and international teammate, potentially crucial in persuading him to move to the Nou Camp.

It’s easy to see why Barcelona admire Aguero. He scored six times against them during his time in La Liga with Atletico Madrid, including two goals in the 4-2 win over the Catalan giants in 2008 and another double in the 4-3 win a year later.

His blistering pace up against Barca’s high back line caused them all sorts of problems, and since his move to the Premier League in 2011, he has continually improved. He is now considered one of the best players in world football. It’s no surprise envious glances are being cast from Spain’s top clubs.

City, though, are in a strong position. Not in need of money and desperate to keep hold of their best players in order to continue their development, it would take a willingness of the player’s part to force a transfer, a situation that seems somewhat unlikely.

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Aguero signed a one-year contract extension in the summer, taking his current deal to June 2017, and he enjoys a special relationship with City’s fans after playing a crucial role in the club’s first title win in 44 years when he scored the most famous goal in Premier League history against QPR in 2012.

What’s becoming increasingly clear, though, is that City must improve their Champions League record to keep a player of Aguero’s calibre. Manuel Pellegrini steered them beyond the group stage for the first time this season—a significant moment psychologically for his squad—but their record in the competition is not good enough to keep a player of Aguero’s quality satisfied.

He's good enough to play for any side in the world, something the City board are well aware of, and progress is needed to keep him happy; investment in the right areas this summer is vital.

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City have a core of players who could easily be deemed world class, and with some defensive reinforcements and a few young, hungry squad players, they could easily find themselves in the elite group of sides capable of Champions League success.

However, they need to reach that level quickly if Aguero is to be a part of their long-term future.

Rob Pollard is Bleacher Report's lead Manchester City correspondent and will be following the club from a Manchester base throughout the 2013-14 season. Follow him on Twitter here: @RobPollard_.